Korean scientists came up with a smart tattoo to monitor health.

The ink is made up of gallium-based liquid metal and carbon nanotubes. Thanks to this, the tattoo turns into a bioelectrode - it can conduct electricity, interact with electronics and serve as a heartbeat or blood sugar sensor. To take readings, the tattoo must be connected to an electronic gadget - it does not have its own source of energy and memory. In the future, scientists want to add a chip to the tattoo. Then the body will be able to communicate directly with external devices.